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1.
Br J Clin Pharmacol ; 89(12): 3681-3689, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37485589

RESUMEN

AIMS: To compare pharmacokinetics (PK) and safety of heat-stable inhaled (IH) oxytocin with intramuscular (IM) oxytocin in women in third stage of labour (TSL), the primary endpoint being PK profiles of oxytocin IH and secondary endpoint of safety. METHODS: A phase 1, randomized, cross-over study was undertaken in 2 UK and 1 Australian centres. Subjects were recruited into 2 groups: Group 1, women in TSL; Group 2, nonpregnant women of childbearing potential (Cohort A, combined oral contraception; Cohort B, nonhormonal contraception). Participants were randomized 1:1 to: Group 1, oxytocin 10 IU (17 µg) IM or oxytocin 240 IU (400 µg) IH immediately after delivery; Group 2, oxytocin 5 IU (8.5 µg) intravenously and oxytocin 240 IU (400 µg) IH at 2 separate dosing sessions. RESULTS: Participants were recruited between 23 November 2016 to 4 March 2019. In Group 1, 17 participants were randomized; received either IH (n = 9) or IM (n = 8) oxytocin. After IH and IM administration, most plasma oxytocin concentrations were below quantification limits (2 pg/mL). In Group 2 (n = 14), oxytocin IH concentrations remained quantifiable ≤3 h postdose. Adverse events were reported in both groups, with no deaths reported: Group 1, IH n = 3 (33%) and IM n = 2 (25%); Group 2, n = 14 (100%). CONCLUSION: Safety profiles of oxytocin IH and IM were similar. However, PK profiles could not be established for oxytocin IH or IM in women in TSL, despite using a highly sensitive and specific assay.


Asunto(s)
Oxitócicos , Hemorragia Posparto , Femenino , Humanos , Australia , Estudios Cruzados , Oxitócicos/efectos adversos , Oxitocina/efectos adversos , Hemorragia Posparto/inducido químicamente
2.
Nanomaterials (Basel) ; 13(2)2023 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-36678015

RESUMEN

Nickel oxide nanoparticles (NiO NPs) have been the focus of many toxicity studies. However, acute toxicity studies that identify toxicological dose descriptors, such as an LC50 or LD50, are lacking. In this paper, the acute toxicity of NiO NPs was evaluated in albino-derived Sprague-Dawley rats through OECD guideline studies conducted by both the oral and inhalation routes of exposure. The animals were assessed for mortality, body weight, behavioral observations, and gross necropsy. Results from previously conducted (unpublished) acute inhalation studies with larger NiO microparticles (MPs) are also included for comparison. Mortality, the primary endpoint in acute toxicity studies, was not observed for rats exposed to NiO NPs via either the oral or inhalation exposure routes, with a determined LD50 of >5000 mg/kg and an LC50 > 5.42 mg/L, respectively. Our results suggest that these NiO NPs do not exhibit serious acute toxicity in rats or warrant an acute toxicity classification under the current GHS classification criteria. This aligns with similar results for NiO MPs from this and previously published studies.

3.
Food Chem Toxicol ; 153: 112267, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34000342

RESUMEN

A novel, highly soluble biotin salt, magnesium biotinate (MgB), was assessed for general and genetic toxicity using several toxicologic tests. This battery of tests included in vitro bacterial reverse mutation test, in vitro mammalian micronucleus assay, and oral acute, 14-day, and 90-day repeat-dose toxicity in Sprague-Dawley (SD) rats. The results of the in vitro studies indicate that MgB is not mutagenic, clastogenic, or aneugenic. The acute oral toxicity study established an LD50 ≥ 5000 mg MgB/kg. In the 14-day oral toxicity study, doses of MgB up to 2500 mg MgB/kg/day produced no clinical signs or mortality. In the 90-day oral toxicity study, administration of 600 mg MgB/kg/day resulted in no clinical signs and was determined to be the no-observed-adverse-effect-level (NOAEL), which equates to 39 g biotin/day for a 70 kg human. Since MgB is composed of 93% biotin, the 600 mg NOAEL equates to approximately 1.3 million times the current recommended daily allowance of 30 µg biotin/day and 3900 times supplement levels of 10 mg biotin/day. Based on the toxicologic profile and lack of findings in various in vitro and in vivo studies, MgB may be considered safe for long-term human use.


Asunto(s)
Biotina/toxicidad , Administración Oral , Animales , Biotina/administración & dosificación , Biotina/química , Línea Celular , Cricetulus , Femenino , Dosificación Letal Mediana , Magnesio/química , Masculino , Nivel sin Efectos Adversos Observados , Ratas Sprague-Dawley , Salmonella typhimurium/efectos de los fármacos , Pruebas de Toxicidad Subcrónica
4.
J Gastrointest Cancer ; 50(1): 84-90, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29177608

RESUMEN

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDA) is associated with poor outcomes and presents oncologists with a myriad of clinical challenges. This study was conducted to assess oncologists' practice patterns and to identify the greatest areas of need for future PDA continuing medical education (CME) programs. METHODS: Case vignettes have been validated as an effective tool to assess how physicians approach and treat a wide array of diseases. In order to assess practice patterns for resectable, locally advanced unresectable, and metastatic PDA, an online case vignette survey was distributed to practicing medical oncologists. RESULTS: Responses from 150 US-practicing oncologists were analyzed, and several key opportunities for future CME programs were identified. For case 1 (patient with resectable PDA), 44% of oncologists did not select an evidence-based adjuvant chemotherapy regimen. For case 2 (patient with locally advanced PDA who develops metastases and neuropathy after first-line nab-paclitaxel/gemcitabine followed by chemoradiation), 57% of oncologists did not select an evidence-based second-line chemotherapy regimen, and 35% selected a regimen containing oxaliplatin, a chemotherapeutic known to cause neuropathy. For case 3 (patient with a pancreatic mass and liver metastases), only 34% of oncologists recommended a biopsy, chest imaging, and liver function tests which should be standard of care assessments with this presentation. For all three cases, clinical trial referral was selected by fewer than 5% of respondents. CONCLUSIONS: This study identified appreciable discrepancies between oncologists' recommendations and standard evidence-based guidelines. Well-designed CME programs may help to bridge the educational gaps identified and improve adherence to practice guidelines.


Asunto(s)
Adenocarcinoma/terapia , Carcinoma Ductal Pancreático/terapia , Evaluación de Necesidades/normas , Oncólogos/educación , Pautas de la Práctica en Medicina/normas , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad
5.
Med J Aust ; 209(11): 503-505, 2018 12 10.
Artículo en Inglés | MEDLINE | ID: mdl-30521446

RESUMEN

OBJECTIVE: To determine whether surgeons and junior doctors intending to pursue careers in surgery are more likely to purchase more expensive vehicles and to replace them sooner than colleagues of similar seniority pursuing non-surgical careers. DESIGN AND SETTING: Survey of practising medical officers at an Australian tertiary referral hospital. MAIN OUTCOME MEASURES: Car value; proportion of doctors who bought their car new; median time to replacement of vehicle. RESULTS: 154 doctors participated in the survey (17% response rate). 49% were interns, residents or unaccredited registrars, 18% were accredited registrars or fellows, and 31% were consultants; 40% of respondents were surgical trainees or consultants. 59% of surgical trainees and consultants purchased their car new, compared with 38% of non-surgical doctors (P = 0.013); 52% of doctors in the junior surgeon group purchased their car new, compared with 28% of non-surgeon junior doctors (P = 0.019). Median car value was $16 500 (IQR, $9350-37 000) for surgeons and $8500 (IQR, $4400-14 100) for non-surgeons (P < 0.001); 30% of surgeons owned cars valued at more than $50 000, compared with 6% of non-surgeons (P = 0.025). The median time to replacement was 5-7 years for surgeons and 7-10 years for non-surgeons (P < 0.001). CONCLUSIONS: Surgeons more frequently purchase their cars new and replace their cars earlier than non-surgeons, and the median value of their vehicles is higher. These findings were consistent across all levels of seniority.


Asunto(s)
Automóviles/economía , Automóviles/estadística & datos numéricos , Cirugía General/educación , Cuerpo Médico de Hospitales , Australia , Selección de Profesión , Femenino , Humanos , Masculino , Autoinforme , Especialidades Quirúrgicas
7.
Appl Environ Microbiol ; 82(23): 6952-6960, 2016 12.
Artículo en Inglés | MEDLINE | ID: mdl-27663026

RESUMEN

Colonization with Oxalobacter formigenes may reduce the risk of calcium oxalate kidney stone disease. To improve our limited understanding of host/O.formigenes and microbe/O.formigenes interactions, germ-free or altered Schaedler flora (ASF) mice were colonized with O.formigenes Germ-free mice were stably colonized with O.formigenes suggesting O.formigenes does not require other organisms to sustain its survival. Examination of intestinal material indicated no viable O.formigenes in the small intestine, ∼4 × 106 O.formigenes per 100mg contents in the cecum and proximal colon, and ∼0.02% of total cecal O. formigenes cells were tightly associated to the mucosa. O.formigenes did not alter the overall microbial composition of ASF, and ASF did not impact O.formigenes capacity to degrade dietary oxalate in the cecum. 24-hour urine and fecal collections within metabolic cages in semi-rigid isolators demonstrated that introduction of ASF into germ-free mice significantly reduced urinary oxalate excretion. These experiments also showed that mono-colonized O.formigenes mice excrete significantly more urinary calcium compared to germ-free mice, which may be due to degradation of calcium oxalate crystals by O.formigenes and the subsequent intestinal absorption of free calcium. In conclusion, the successful establishment of defined-flora O.formigenes mouse models should improve our understanding of O.formigenes host and microbe interactions. These data support the use of O.formigenes as a probiotic that has limited impact on the composition of the resident microbiota but providing efficient oxalate degrading function. IMPORTANCE: Despite evidence suggesting a lack of O. formigenes colonization is a risk factor for calcium oxalate stone formation, little is known about O. formigenes biology. This study is the first to utilize germ-free mice to examine the response to mono-colonization with O. formigenes and the impact of a defined bacterial cocktail, altered Schaedler flora, on O. formigenes colonization. This study demonstrates that germ-free mice on their regular diet remain mono-colonized with O. formigenes, and suggests that further studies with O. formigenes gnotobiotic mouse models could improve our understanding of O. formigenes biology and host/O. formigenes and microbe/O. formigenes interactions.

8.
Arch Microbiol ; 198(10): 1019-1026, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27449000

RESUMEN

Oxalobacter formigenes (O. formigenes) is a nonpathogenic, Gram-negative, obligate anaerobic bacterium that commonly inhabits the human gut and degrades oxalate as its major energy and carbon source. Results from a case-controlled study suggested that lack of O. formigenes colonization is a risk factor for recurrent calcium oxalate stone formation. Hence, O. formigenes colonization may prove to be an efficacious method for limiting calcium oxalate stone risk. However, challenges exist in the preparation of O. formigenes as a successful probiotic due to it being an anaerobe with fastidious growth requirements. Here we examine in vitro properties expected of a successful probiotic strain. The data show that the Group 1 O. formigenes strain OxCC13 is sensitive to pH < 5.0, persists in the absence of oxalate, is aerotolerant, and survives for long periods when freeze-dried or mixed with yogurt. These findings highlight the resilience of this O. formigenes strain to some processes and conditions associated with the manufacture, storage and distribution of probiotic strains.


Asunto(s)
Microbioma Gastrointestinal , Oxalatos/metabolismo , Oxalobacter formigenes/crecimiento & desarrollo , Oxalobacter formigenes/metabolismo , Probióticos/metabolismo , Carbono/metabolismo , Metabolismo Energético/fisiología , Humanos , Factores de Riesgo
9.
J Proteomics Bioinform ; 9(1): 19-24, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26924912

RESUMEN

Oxalobacter formigenes is a unique intestinal organism that relies on oxalate degradation to meet most of its energy and carbon needs. A lack of colonization is a risk factor for calcium oxalate kidney stone disease. The release of the genome sequence of O. formigenes has provided an opportunity to increase our understanding of the biology of O. formigenes. This study used mass spectrometry based shotgun proteomics to examine changes in protein levels associated with the transition of growth from log to stationary phase. Of the 1867 unique protein coding genes in the genome of O. formigenes strain OxCC13, 1822 proteins were detected, which is at the lower end of the range of 1500-7500 proteins found in free-living bacteria. From the protein datasets presented here it is clear that O. formigenes contains a repertoire of metabolic pathways expected of an intestinal microbe that permit it to survive and adapt to new environments. Although further experimental testing is needed to confirm the physiological and regulatory processes that mediate adaptation with nutrient shifts, the O. formigenes protein datasets presented here can be used as a reference for studying proteome dynamics under different conditions and have significant potential for hypothesis development.

11.
Appl Environ Microbiol ; 81(15): 5048-54, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25979889

RESUMEN

Animal and human studies have provided compelling evidence that colonization of the intestine with Oxalobacter formigenes reduces urinary oxalate excretion and lowers the risk of forming calcium oxalate kidney stones. The mechanism providing protection appears to be related to the unique ability of O. formigenes to rely on oxalate as a major source of carbon and energy for growth. However, much is not known about the factors that influence colonization and host-bacterium interactions. We have colonized mice with O. formigenes OxCC13 and systematically investigated the impacts of diets with different levels of calcium and oxalate on O. formigenes intestinal densities and urinary and intestinal oxalate levels. Measurement of intestinal oxalate levels in mice colonized or not colonized with O. formigenes demonstrated the highly efficient degradation of soluble oxalate by O. formigenes relative to other microbiota. The ratio of calcium to oxalate in diets was important in determining colonization densities and conditions where urinary oxalate and fecal oxalate excretion were modified, and the results were consistent with those from studies we have performed with colonized and noncolonized humans. The use of low-oxalate purified diets showed that 80% of animals retained O. formigenes colonization after a 1-week dietary oxalate deprivation. Animals not colonized with O. formigenes excreted two times more oxalate in feces than they had ingested. This nondietary source of oxalate may play an important role in the survival of O. formigenes during periods of dietary oxalate deprivation. These studies suggest that the mouse will be a useful model to further characterize interactions between O. formigenes and the host and factors that impact colonization.


Asunto(s)
Oxalatos/metabolismo , Oxalobacter formigenes/crecimiento & desarrollo , Oxalobacter formigenes/metabolismo , Orina/química , Animales , Carbono/metabolismo , Dieta , Metabolismo Energético , Heces/química , Humanos , Ratones , Modelos Animales
12.
Urology ; 85(3): 517-21, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25733259

RESUMEN

OBJECTIVE: To examine the levels of Oxalobacter formigenes in probiotic supplements marketed by PRO-LAB, Ltd, Toronto, Canada, and capsules of Oxalo purchased from Sanzyme Ltd, Hyderabad, India, and to measure the ability of these preparations to degrade oxalate in vitro. METHODS: Probiotic supplements and pure cultures of O. formigenes were cultured in a number of media containing oxalate. Optical density at 595 nm (OD595) was used to measure bacterial growth, and ion chromatography was used to measure loss of oxalate in culture media. O. formigenes-specific and degenerate Lactobacillus primers to the oxalate decarboxylase gene (oxc) were used in polymerase chain reaction (PCR). RESULTS: Incubating probiotic supplements in different media did not result in the growth of oxalate-degrading organisms. PCR indicated the absence of organisms harboring the oxc gene. Culture and 16S ribosomal ribonucleic acid gene sequencing indicated the PRO-LAB supplement contained viable Lactococcus lactis subsp. lactis (GenBank accession no. KJ095656.1), whereas Oxalo contained several Bacillus species and Lactobacillus plantarum. CONCLUSION: The probiotic supplement sold over the Internet by PRO-LAB Ltd and Sanzyme Ltd did not contain identifiable O. formigenes or viable oxalate-degrading organisms, and they are unlikely to be of benefit to calcium oxalate kidney stone patients.


Asunto(s)
Suplementos Dietéticos , Cálculos Renales/terapia , Oxalatos/metabolismo , Oxalobacter formigenes/metabolismo , Probióticos/uso terapéutico , Técnicas Bacteriológicas , Oxalobacter formigenes/genética
13.
Ther Innov Regul Sci ; 47(1): 125-132, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30227488

RESUMEN

Patients in the United States receive multiple forms of written drug information with their prescription medicines. This study solicited consumers' preferences about formatting of information, their motivation to read drug information, and their ability to navigate and understand the information. A 3 × 3 study design was used in which 3 prototypes for 3 prescription drugs, ORTHO TRI-CYCLENTM (norgestimate/ethinyl estradiol), COUMADINTM (warfarin sodium), and PARNATETM (tranylcypromine sulfate), were evaluated. The prototypes included 2 novel formats ("new" and "bubble") and the "current" format that patients now commonly receive with their prescriptions. A total of 105 consumers participated in the study. Consumers correctly answered more questions about the medicine when presented with a new (70%-95%) or a bubble prototype (83%-92%) than with the current format (53%-74%). All attributes scored higher with both prototypes compared with the current format. However, in terms of overall preference, consumers favored the new prototype and indicated that they would be more motivated to read it. Consumers also reported that simple icons assisted them in finding important information. The new and bubble prototypes were favored by participants more than the current format. Key attributes preferred by consumers must be considered as new formats for patient medication information are developed.

15.
J Am Acad Dermatol ; 55(6): 1014-23, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17110217

RESUMEN

BACKGROUND: Male pattern hair loss (MPHL) is a potentially reversible condition in which dihydrotestosterone is an important etiologic factor. OBJECTIVE: Our aim was to evaluate the efficacy of the type 1 and 2 5alpha-reductase inhibitor dutasteride in men with MPHL. METHODS: Four hundred sixteen men, 21 to 45 years old, were randomized to receive dutasteride 0.05, 0.1, 0.5 or 2.5 mg, finasteride 5 mg, or placebo daily for 24 weeks. RESULTS: Dutasteride increased target area hair count versus placebo in a dose-dependent fashion and dutasteride 2.5 mg was superior to finasteride at 12 and 24 weeks. Expert panel photographic review and investigator assessment of hair growth confirmed these results. Scalp and serum dihydrotestosterone levels decreased, and testosterone levels increased, in a dose-dependent fashion with dutasteride. LIMITATIONS: The study was limited to 24 weeks. CONCLUSION: Dutasteride increases scalp hair growth in men with MPHL. Type 1 and type 2 5alpha-reductase may be important in the pathogenesis and treatment of MPHL.


Asunto(s)
Inhibidores de 5-alfa-Reductasa , Alopecia/tratamiento farmacológico , Antagonistas de Andrógenos/uso terapéutico , Azaesteroides/uso terapéutico , Finasterida/uso terapéutico , Adulto , Alopecia/enzimología , Antagonistas de Andrógenos/administración & dosificación , Antagonistas de Andrógenos/efectos adversos , Antagonistas de Andrógenos/farmacología , Azaesteroides/administración & dosificación , Azaesteroides/efectos adversos , Azaesteroides/farmacología , Dihidrotestosterona/análisis , Dihidrotestosterona/sangre , Relación Dosis-Respuesta a Droga , Dutasterida , Finasterida/administración & dosificación , Finasterida/efectos adversos , Finasterida/farmacología , Cabello/efectos de los fármacos , Cabello/crecimiento & desarrollo , Humanos , Isoenzimas/antagonistas & inhibidores , Libido/efectos de los fármacos , Masculino , Persona de Mediana Edad , Cuero Cabelludo/química , Cuero Cabelludo/efectos de los fármacos , Testosterona/análisis , Testosterona/sangre , Resultado del Tratamiento
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